Reducing greenhouse gas (GHG) emissions through energy reduction in buildings is a high priority for policy-makers in the European Union and elsewhere. However, although long-term sustainability targets exist on the societal level, it is not obvious how these targets may trickle down to individual sectors and further down to specific organizations or buildings. The aim of this paper is to illustrate an approach for evaluating renovation measures in order to identify appropriate target levels in early project stages and what is needed to achieve a number of proposed sustainability targets. The evaluation approach is supported by a tool that can be seen as an aid to making rough estimations of the environmental impacts. Sustainability target levels in a Swedish context are presented for three issues: operational energy use, GHG emissions due to total energy use for building operation, and embodied GHG emissions due to production of materials. The approach to support well-grounded retrofit decisions is shown with a case study. The tool developed, in combination with a suggested step-by-step evaluation approach, provides an effective way to evaluate various potential improvements, and their consequences, in early project stages. However, other tools with similar functionality may be used. Results from the case illustration imply that it is possible to achieve the proposed sustainability targets for operational energy use by implementing nine measures. However, the targets for GHG emissions for operational energy use and embodied GHG emissions were not achieved because of an energy supply with too high a share of non-renewable fuels.

In many European countries, there are building stocks in need of extensive renovation. This constitutes an important opportunity to perform energy-saving measures and improve indoor environmental quality aiming at a more sustainable built environment. In this paper, we report results from an interview study with the aim of obtaining an in-depth understanding of renovation processes and how sustainability aspects are handled by various Swedish property owners. Examples of important barriers revealed in the interviews are insufficient inspection of existing buildings, absence of both overarching and detailed sustainability targets and guidelines, and lack of knowledge about sustainability aspects. Based on the interview study, conclusions are drawn for the further development of a process model which aims at systematize integration and effectively address energy, environmental, and indoor environmental quality aspects throughout a renovation process; we refer to this as sustainable renovation. Some key starting points for the process model are to suggest routines, provide checklists and tools, and offer guidance for formulating sustainability targets. However, the interviews show that in order to reach a more sustainable built environment, there is a need for government subsidies, other incentives or new business models that value environmental aspects higher.

Understanding how Building Environmental Assessments Tools (BEATs) measure and define “environmental” building is of great interest to many stakeholders, but it is difficult to understand how BEATs relate to each other, as well as to make detailed and systematic tool comparisons. A framework for comparing BEATs is presented in the following which facilitates an understanding and comparison of similarities and differences in terms of structure, content, aggregation, and scope. The framework was tested by comparing three distinctly different assessment tools; LEED-NC v3, Code for Sustainable Homes (CSH), and EcoEffect. Illustrations of the hierarchical structure of the tools gave a clear overview of their structural differences. When using the framework, the analysis showed that all three tools treat issues related to the main assessment categories: Energy and Pollution, Indoor Environment, and Materials and Waste. However, the environmental issues addressed, and the parameters defining the object of study, differ and, subsequently, so do rating, results, categories, issues, input data, aggregation methodology, and weighting. This means that BEATs measure “environmental” building differently and push “environmental” design in different directions. Therefore, tool comparisons are important, and the framework can be used to make these comparisons in a more detailed and systematic way.

The paper deals with the development of a tool used for the life cycle assessment of residential buildings located in three different European towns: Brussels (Belgium), Coimbra (Portugal) and Lulea (Sweden). The basic tool focuses on the structure and the materials of the buildings and permits the evaluation of the Embodied energy, Embodied carbon and yearly energy consumption. For that purpose, a different set of original data is taken into account for each location, in which the monthly temperatures, energy mix, heating and cooling systems are defined. The energy consumption, being for heating space or water, for cooling or for lighting is transformed into CO2 emissions to deduce the Operational carbon as well. The influence of the energy mix can therefore be assessed in the basic tool. As a matter of fact, the heating and cooling systems habitually used in the three countries are also of great importance. The District Heating system, is, for instance, incorporated in the basic tool. The presence of solar water heater or photovoltaic panels is also strongly influencing the operational carbon. After a short literature review on building LCA and the description of the basic tool, the software Pleiades + Comfie combined with Equer is used to achieve the complete LCA for one building using two different load bearing frames. The results of the calculations for Brussels climate are verified against these software results. The dependence of the results to parameters such as climate, energy mix and habits is then discussed in the companion paper.

In 2003, a joint effort between the Swedish government, a number of companies in the building and construction sectors, some municipalities, insurance companies and banks set a target that by 2009, all new buildings and 30% of existing Swedish buildings should be rated using a voluntary environmental rating tool. In a major research programme finished in 2008, a tool was developed to be used in this context. The tool covers three assessment areas: Energy, Indoor environment and Material & Chemicals. These areas are split into 11 aspects with one or a few indicators. Rating criteria are specified for each indicator, stipulating requirements for a rating Gold, Silver, Bronze and Rated. Indicator results can then be aggregated to aspect, area and a single raring for building level for enhanced result communication. The tool builds on previous experiences regarding environmental building rating tools and therefore includes some special characteristics which aim to tackle some of the criticism directed towards the first generation of such tools. At the time of writing, the first buildings have received official ratings and an independent stakeholder group is promoting broader implementation of the tool. (C) 2010 Elsevier Ltd. All rights reserved.

This study examined whether simplified life cycle-based calculations of climate change contributions can provide better decision support for building design. Contributions to climate change from a newly built office building in Gävle, Sweden, were studied from a life cycle perspective as a basis for improvements. A basic climate and energy calculation tool for buildings developed in the European project ENSLIC was used. The study also examined the relative impacts from building material production and building operation, as well as the relative importance of the impact contributions from these two life cycle stages at various conditions.

The ENSLIC tool calculates operational energy use and contributions to climate change of a number of optional improvement measures. Twelve relevant improvement measures were tested. The most important measures proved to be changing to CO₂ free electricity, changing construction slabs from concrete to wood, using windows with better U-values, insulating the building better and installing low-energy lighting and white goods. Introduction of these measures was estimated to reduce the total contribution to climate change by nearly 50% compared with the original building and the operational energy use by nearly 20% (from 100 to 81 kWh/m² yr). Almost every building is unique and situated in a specific context. Making simple analyses of different construction options showed to be useful and gave some unexpected results which were difficult to foresee from a general design experience. This process acts as an introduction to life cycle thinking and highlights the consequence of different material choices.

Environmental assessment tools for buildings are emerging rapidly in many countries. Do different assessment tools influence the design process and also guide ‘green’ building projects in different directions? Three assessment tools, Leadership in Energy and Environmental Design for New Construction (LEED-NC), Code for Sustainable Homes (CSH) and EcoEffect, were tested in a case study project in Sweden: a new multi-storey residential building called Grönskär. The content and results of the three assessment tools were compared in general, while issues in the three core common categories of Energy, Indoor Environment and Materials & Waste were compared in more detail. The assessment results for the case study building varied with the three tools, and the design strategies and tactics to improve the overall rating of the building project differed for each tool. This confirms that the tools can influence sustainable building in different directions and illustrates insufficient consensus between assessment tools in terms of issues, criteria and weighting. The divergent results highlight the need for an appropriate structure of assessment tools that are both environmentally relevant and practically useful.